Stop-watch



2 Sheets-$heet 2. H. J. EI'SEN.

. STOP 'WATGH.

(No Model.)

No. 437,683. Patented Oct. 7, 1890.

Herman film 07L Zk'sen.

& W m m a M mw UNITED STATES PATENT OFFICE.

HERMAN J. EISEN, OF BROOKLYN, NEW YORK.

STOP-WATCH SPECIFICATION forming part of Letters Patent No. 437,683, dated October 7, 1890.

Application filed May 17, 1890. Serial No. 352,126. (No model.)

To all whom it may concern:

Be it known that I, HERMAN JOSEPH EISEN, a citizen of the United States, and a resident of Brooklyn, in the State of New York, doing business at No. 39 Maiden Lane, New York city, have invented a new and useful Improvement in Stopatches, of which the following is a specification.

This invention relates to that class of stopwatches in which a splitseconds hand is driven from the fourth-wheel arbor of the main train, and primarily to those in which the split-seconds hand is under the control of a cam-wheel that is turned step by step at will, the split-seconds hand being started by a first actuation of the cam-wheel, stopped by a second actuation thereof, and reset or re turned to its starting-point by a third actuation of the same.

The present improvement consists in certain novel combinations of parts, hereinafter set forth and claimed, whereby fine-toothed wheels, which constitute the split-seconds train, are meshed and nnmeshed by movements in and out of the fourth-wheel arbor itself without at all interfering with the main train of the watch. The movable bearing of the fourth-wheel arbor and a lever and spring to coact with the same and with the camwheel are combined in a single simple part, which in the preferred arrangement also supports a pinion in constant mesh with the outer wheel of the split-seconds train, and a pair of spring-1evers to coact, respectively, with the stop-wheel and with the heart-cam on the split-seconds arbor are adapted to be raised and lowered in proper succession by the camwheel at one and the same side of the latter.

The general objects of the invention are to dispense with every unnecessary part, to prevent lost motion, and to construct the stop mechanism on a principle that is applicable to the movements of various makes of watches which have not heretofore been converted into stop-watches.

Two sheets of drawings accompany this specification as part thereof.

Figure 1 of these drawings is a face view of a stop-watch, illustrating the invention. Fig. 2 is a back view of the same with its back and cap-bezel removed. Figs. 3 and 4; are magnified back views of the works removed from the case, showing the split-seconds train started and stopped, respectively. Fig. 5 represents a section on the line 5 5, Fig. i; and Figs. 6 and '7 are perspective views of certain parts detached. Portions shown in section in Figs. 2 and 4 are broken away to expose parts behind.

Like letters refer to like parts in the several figures.

The split-seconds hand 71, Figs 1 and 5, of the particular stop-watch shown in the draw ings, revolves in front of the hour, minute, and seconds hands a b 0 before a suitable dial d at the face of the watch, and the split-see onds train, hereinafter described, is arranged at the back of the main movement, as shown in Figs. 2 to 4, together with the whole of the starting, stopping, and resetting mechanism, excepting atubnlar slide or follower f, (shown detached by Fig. 6,) which coacts with the movable crown e of the stem of the watch, as shown in Fig. 2. This is the preferred arrangement, and for clearness the following description will be confined to the improved movement, as shown.

The fourth-wheel arbor a of the main train has an ordinary front bearing in the front plate f of the works, except that it is adapted to oscillate therein, and care is taken that its hole in the dial (1 permits such oscillation. It has no bearing in the back plate b of the main movement, but passes freely through an opening in the same, and has its back bearing 11 in a combined spring and lever 3. (Shown detached by Fig. 7.) The back pivot of the arbor a is extended through the movable bearing thus formed, and carries outside of the same the outer wheel to of a fine-toothed split-seconds train. A stud-pivot for a pinion 1) in constant mesh with said outer wheel w is carried by an arm a of said. spring-lever s, and the center wheel or stop-wheel 10 of the train (the split-seconds train) is fast on the arbor ct of the split-seconds hand h. This arbor c has its front bearing within a tubular minute-hand arbor a Fig. 5, and its back bearing is a small back plate 12 attached to said back plate 1). Immediately behind said back bearing and outside of said wheel 10 said arbor a is provided with its heart-cam h, exposed to View in Fig. 4. Normally the fourth-wheel arbor a is perpendicular to the front and back plates f b, and is steadily supported in this position by the spring-lever s. The split-seconds train is open, said pinion 10 being in mesh only with said outer wheel 10, which turns continuously with the fourth-wheel arbor, and the split-seconds hand his kept at zero or the starting-point by the coaction with said heart-cam h of the beveled head of a spring-lever s in an ordinary manner. The watch is represented as in this condition in Figs. 1 and 2. In startingthe splitseconds hand from zero by a pressure on the crown e a finger f Fig. 6, at the inner end of said follower f coacts with the upper end of a lever Z, Figs. 2 to 4, attached at mid-length bya pivotal screwz to said back plate I). A spring-pawl 19', Figs. 3 and 4, carried by the lower end of said lever l, coacts with aratchetwheel 1' of twelve teeth, which carries on its outer side a cam-wheel c of four notches, and turns on a screw y, Figs. 3 and 4, tapped into said back plate I). Said cam-wheel thus receives a one-twelfth turn. A beveled projection at mid-length on said spring-lever s which normally occupies one of said notches, as in Fig. 2, is cammed out and supported against a solid portion of the periphery of the cam-wheel, as in Figs. 3 and 4, so as to free the heart-cam h. The beveled head h ,Fig. 7, of said spring -lever s, which normally presses against a solid portion of the periphery of the cam-wheel between two of said notches,

as in Fig. 2, is permitted to enter a notch,as

in Fig. 3, and swings inward. The back end of the fourth-wheel arbor a and the studpivot of the pinion p are carried inward therewith, so as to close the split-seconds train w I 19 w as shown in Fig. 3, and the hand h instantly starts at the speed of the seconds hand 0 and in the same direction. When the crown e is freed from pressure, it is re-elevated by a spring 8, Figs. 2 to 4, attached to the back plate 19 by a screw w, Figs. 3 and 4, and pressing against the lower end of said lever I. Should the crown be held down no harm can result. A stop-pin q, Figs. Sand 4, limits the movement of the lever l by said spring 8', and a spring-detent d in constant mesh with said ratchet-wheel r keeps the cam-wheel To stop the split-seconds hand, the crown eis again depressed, and through the follower f, lever l,

.pawl p, and ratchet-wheel r the cam-wheel .c' is turned from its position represented by Fig. 3-to its position represented by Fig. 4.

During this actuation of the cam-wheel the spring-lever s is cammed out to its said normal posi tion, reopening the split-seconds train, and a spring-lever 3 previously held back by the coaction of a beveled mid-length projection thereon with the solid portion of the periphery of the cam-wheel, as in Figs. 1, 2, and 3, is permitted to press against the periphery of the stop-wheel w so as to instantly arrest the rotation of the latter, and thus -to stop and hold the hand it at that point of the dial where it happens to be. To reset of operations and restores the parts to the positionsrepresented by Figs. 1 and 2, as above. The ratchet-wheel r is arranged within a depression or surface recess 0", Figs. 3 to 5, formed in the back plateb', and circularholding ends h 71 Figs. 3 to 5 and Fig. 7, on sa d spring-lever s and detent d are let into said back plate to the same plane and pinned fast. An offset 0, Fig. 7, in the spring-lever s, adapts its head end to work outside of the detent d and to coact with the cam-wheel. The fixed ends of the spring-levers s s are attached, adjoining each other, to the main surface of the back plate 12' at its perimeter by screws 0: :0 Figs. 3 and 4. Said lever s is set so as to work across and outside of said lever 5 and the beveled projection of the former is formed nearer the perimeter of the back plate than that of the other, so that it cannot spring inward until after the stop-lever s is cammed out of contact with the fine-toothed periphery of the stop-wheel.

Details which have not been specified may be. of any approved description, and I do not limit my respective claims as to mechanical details except as therein stated.

The main movement represented in the drawings is of an ordinary make well known to the trade and forms no part of this inven- .fine-toothed split-seconds train, the outer and stop wheels of which are carried by said. fourth-wheel arbor and by said split-seconds arbor, respectively, substantially as hereinbefore specified. a

2. In combination with a movable fourthwheel arbor, a spring-lever forming its movable bearing, substantially as hereinbefore specified. Y

3. The spring-lever s, constructed with the bearing 12 and arm a in combination with the fourth-wheel arbor a pivoted in said bearing and carrying the wheel 10 at its back end, the pinion p, pivoted on said arm, in conl distances from their fixed outer ends, in com- 10 stant mesh with said wheel, the stop-wheel binat-ion with the cam-Wheel c,heart-oam h, 10 meshed by said pinion at will, a split-seestop-Wheel w arbor a, and split-seconds onds arbor on which said stop-wheel is fast, hand h, substantially as hereinbefore speci- 5 and a split-seconds hand carried by the front fied end of said arbor, substantially as hereinbe- HERMAN J. EISEN. fore specified. lVitnesses:

4. The adjoining spring-levers s 5 having TIMOTHY DAVENPORT,

beveled mid-length projections at difierent AUSTIN E. PRESSINGER. 

